$fname = "john";
$lname = "doe";
$ctry = "canada";
my $url = 'https://www.google.com/?firstname=$fname&lastname=$lname&country=$ctry';
print "Requesting ", $url, "\n";
my $req = HTTP::Request->new(GET => $url);

##</code><code>##

my $single_quoted = 'https://www.google.com/?firstname=$fname&lastname=$lname&country=$ctry';
my $double_quoted = "https://www.google.com/?firstname=$fname&lastname=$lname&country=$ctry";

print 'Single quotes:', $single_quoted, "\n";
print "Double quotes:", $double_quoted, "\n";